Laundry apparatus

ABSTRACT

A laundry dryer is provided with a heated enclosure containing a heat exchanger. Water is pumped to a hot water heater through a conduit which is connected to the heat exchanger so that the water is pre-heated by the heat exchanger. The pump and a valve are connected in the conduit and are operated in response to a thermostatic control for the water heater which opens the valve and starts the pump when the water heater requires hot water. The pre-heating of the water in the heat exchanger cuts down on heating requirements of the water heater, thus economizing on power costs for the water heater.

United States Patent Vaughn Nov. 13, 1973 LAUNDRY APPARATUS [76]Inventor: Donald E. Vaughn, 3105 Southside 'W 7 Camby Blvd.,Jacksonville, Fla. 32216 Asslsmn' [hammer-James Yeung Att0rneyJohn H.Oltman et al. [22] Filed: Mar. 21, 1972 Appl. No.: 236,675

[57] ABSTRACT A laundry dryer is provided with a heated enclosurecontaining a heat exchanger. Water is pumped to 11 hot water heaterthrough a conduit which is connected to the heat exchanger so that thewater is pre-heated by the heat exchanger. The pump and a valve areconnected in the conduit and are operated in response to a thermostaticcontrol for the water heater which opens the valve and starts the pumpwhen the water heater requires hot water. The pre-heating of the waterin the heat exchanger cuts down on heating requirements of the waterheater, thus economizing on power costs for the water heater.

4 Claims, 2 Drawing Figures -25 22 V 21 2a v 1 P v 1 31 I2 1 30 23 IL J-g5 PATENIEDImv 13 I973 HQL LAUNDRY APPARATUS BACKGROUND OF THEINVENTION U.S. Pat. No. 3,157,391 describes and claims a heat vreclaimer in which heat from a laundry dryer is partly vented through anexhaust and is partly recirculated back through the drier. The heatreclaimer includes an enclosure mounted above the dryer. The presentinvention provides a heat exchanger in such an enclosure for pre-heatingwater being supplied to a main water heater for a laundry system. Thus,the invention makes use of the heat of a laundry dryer to pre-heat waterbeing supplied to a water heater, and thus cut down on heatingrequirements of the water heater and also fuel costs for the waterheater.

SUMMARY OF THE INVENTION In a typical laundry installation of theinvention, a water heater having a thermostatic control supplies waterto a plurality of washers. A plurality of laundry dryers are providedwith an enclosure heated by heat from the dryer, and heat exchangermeans is mounted in each enclosure. A conduit is connected through theheat exchanger means in series to the hot water heater, and a pump and avalve are connected in the conduit. When the water heater requires hotwater as sensed by the thermostatic control, this control opens thevalve and turns on the pump so that the pump can supply water pre-heatedby the heat exchanger means to the water heater. Since the water cominginto the water heater is pre-heated, less heat is required in the waterheater and therefore less fuel or power is required for the waterheater.

Accordingly, it is an object of the present invention to save fuel costsin a laundry system such as might be used in a commercial laundry.

Another object of the invention is to pre-heat water being supplied to ahot water heater in a laundry system.

Another object of the invention is to utilize heat from laundry dryersin a laundry system to pre-heat water being supplied to a water heater.

A further object of the invention is to thermostatically control a pumpand a valve in a conduit leading through heat exchanger means to a waterheater so as to automatically supply water through the heat exchangermeans to the heater when the heater requires hot water.

Other objects of this invention will appear from the followingdescription and appended claims, reference being had to the accompanyingdrawings forming a part of this specification wherein like referencecharacters designate corresponding parts in the several views.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic diagram oflaundry apparatus in accordance with a preferred embodiment of theinvention; and

FIG. 2 is a fragmentary perspective view of a laundry dryer providedwith a heated enclosure containing heat exchanger means for pre-heatingwater supplied to the water heater in the apparatus of FIG. 1.

Before explaining the present invention in detail, it is to beunderstood that the invention is not limited in its application to thedetails of construction and arrangement of parts illustrated in theaccompanying drawings, since the invention is capable of otherembodiments and of being practiced or carried out in various ways. Also,it is to be understood that the phraseology or terminology employedherein is for the purpose of description and not of limitation.

DETAILED DESCRIPTION The apparatus 10 of FIG. 1 includes a plurality oflaundry dryers each designated 11. These dryers may be of the type whichare commonly used in coin operated laundry systems. Each of these dryersis provided with a heated enclosure 12 at its top, and each of theheated enclosures 12 may be constructed in accordance with FIG. 2. Itmay be seen that there is a slot 13 communicating the interior of thedryer with the enclosure 12. There is also a vent stack 14 through whichheat is vented from the dryer 11. The vent stack may connect with thedryer at the bottom in the manner shown in US. Pat. No. 3,157,391.Accordingly, the disclosure of said patent is incorporated herein byreference. The vent stack 14 communicates through conduit 15 with theenclosure 12. A blower forces air upwardly through the conduit 14, and adamper at the juncture of conduits 14 and 15 directs part of the heatback through the conduit 15 into the enclosure 12 and past a gas burnerin the dryer 1 l. The heat may flow through the slot 13 back downwardinto the dryer 11.

Mounted in the enclosure 12 is a heat exchanger 16 which may consist ofa few coils of a pipe 17. The heat exchanger 16 is preferably made ofcopper pipe since this material conducts heat well. A heat exchanger 16is provided in each of the enclosures 12 for the dryers 11.

The apparatus 10 includes a hot water heater 18 which has a thermostaticcontrol 19. Such hot water heaters with a thermostatic control aresupplied commerically. There is a main water supply conduit 20 in whichfresh cold water is available. A branch conduit 21 with a valve 22 leadsfrom conduit 20 to the bottom of the water heater 18. When valve 22 isopened, cold water is supplied to the bottom of the water heater in theconventional manner. The conduit 17 connects from the main conduit 20through all of the heat exchanger means 16 in series to the top of thewater heater 18. A pump 23 is connected in the conduit 17, and a valve24 is connected in the conduit 17 between the pump 23 and the firstenclosure 12 of the series. The valve 24 and the pump 23 areelectrically connected by wiring 25 to the thermostat control 19 of thewater heater. The valve 24 and the pump 23 are thermostaticallycontrolled, and such valves and pumps are available commercially.

In operation, when the hot water heater 18 requires hot water, thethermostatic control 19 automatically starts the pump 23 and opens thevalve 24. The pump 23 is preferably a slow moving pump so that it pumpswater at a slow rate through the conduit 17 and through all of the heatexchangers 16 to the top of the hot water heater 18. As the water passesthrough each of the heat exchangers 16 in the enclosures 12, heat in theenclosures 12 is transferred to the water through the heat exchangers16. This heat raises the temperature of the water, and of course eachheat exchanger in the series raises the temperature a little more thanthe preceding heat exchanger. Thus, by the time the water reaches theheater 18, it is considerably pre-heated.

Because of the pre-heating of the water, less heating is required in thewater heater 18 in order to keep the water up to the desiredtemperature. This cuts down on power or fuel costs of the water heater.For example, where a gas water heater is used, less gas is needed toheat the water.

In most laundry installations, the apparatus 10 will also include aplurality of laundry washers, each of which is designated 26 in FIG. 1.A conduit 27 with a valve 28 leads from the heater 18 through branchpipes 29 to each of the washers 26. These conduits supply hot water tothe washers 26 in response to automatic controls included in thewashers. Another conduit 30 with a valve 31 leads from the main watersupply conduit 20 through branch conduit 32 to each of the washers 26.These conduits supply cold water to the washers 26 in response toautomatic controls included within the washers.

Thus, the invention provides for pre-heating of water being supplied toa water heater in a laundry system so as to cut down on the heat neededin the water heater to bring the water up to the required temperatureand also to reduce the power requirements of the water heater. The powersaving is substantial. The water is pre-heated in heat exchanger meansprovided in laundry dryers of the laundry system. Water is pumpedthrough the heat exchangers in series so that each heat exchanger adds alittle more heat to the water and thus gradually brings it up to thefinal temperature where it enters the water heater.

Having thus described my invention, I claim:

1. Laundry apparatus comprising,

a water heater,

a thermostatic control for said water heater,

a laundry dryer having an enclosure at the top thereof heated by heatfrom said dryer,

means for recirculating heat of said dryer through said enclosure andback into said dryer,

heat exchanger means mounted in said enclosure,

conduit means to supply fresh water to said water heater,

said conduit means including a conduit connected through said heatexchanger means to said water heater,

a pump connected in said conduit for pumping water through the same at'arelatively slow rate, and

a valve in said conduit between said pump and said water heater forcontrolling the flow of water in said conduit,

said pump and said valve having means to operate the same in response tosaid thermostatic control to open said valve and start said pump whensaid water heater requires hot water, so that said pump can supply waterpre-heated by said heat exchanger means in said enclosure to said waterheater.

2. The laundry apparatus as claimed in claim 1 in which said apparatusincludes at least one additional clothes dryer having a heated enclosurewith further heat exchanger means therein, and said conduit is connectedthrough said first and second named heat exchanger means in series tosaid water heater.

3. In combination with a laundry dryer having a laundry drying chamber,a vent stack extending up from said drying chamber, an enclosure abovesaid drying chamber, a bypass conduit extending from said vent stack tosaid enclosure for passing heated air to the latter, and means forpassing heated air from said enclosure back down into said dryingchamber, the improvement which comprises:

heat exchange water pipe means positioned in said enclosure to be heatedby the hot air flowing therethrough from said bypass conduit to saiddrying chamber;

and means connecting said heat exchange water pipe means between a watersupply and a hot water tank for preheating the water supplied to thelatter.

4. A laundry system comprising a hot water tank for supplying hot waterto washers;

water supply means for said tank;

a plurality of dryers, each having a laundry drying chamber, a ventstack extending up from said drying chamber, an enclosure above saiddrying chamber, a bypass conduit extending from said vent stack to saidenclosure for passing heated air to the latter, and means for passingheated air from said enclosure back down into said drying chamber;

a plurality of heat exchange water pipes positioned respectively in saidenclosures to be heated by the hot air flowing therethrough from thecorresponding bypass conduit to the respective drying chamher;

and means connecting said heat exchange water pipes in series with eachother between said water supply means and said hot water tank to preheatthe water supplied to the latter.

1. Laundry apparatus comprising, a water heater, a thermostatic controlfor said water heater, a laundry dryer having an enclosure at the topthereof heated by heat from said dryer, means for recirculating heat ofsaid dryer through said enclosure and back into said dryer, heatexchanger means mounted in said enclosure, conduit means to supply freshwater to said water heater, said conduit means including a conduitconnected through said heat exchanger means to said water heater, a pumpconnected in said conduit for pumping water through the same at arelatively slow rate, and a valve in said conduit between said pump andsaid water heater for controlling the flow of water in said conduit,said pump and said valve having means to operate the same in response tosaid thermostatic control to open said valve and start said pump whensaid water heater requires hot water, so that said pump can supply waterpre-heated by said heat exchanger means in said enclosure to said waterheater.
 2. The laundry apparatus as claimed in claim 1 in which saidapparatus includes at least one additional clothes dryer having a heatedenclosure with further heat exchanger means therein, and said conduit isconnected through said first and second named heat exchanger means inseries to said water heater.
 3. In combination with a laundry dryerhaving a laundry drying chamber, a vent stack extending up from saiddrying chamber, an enclosure above said drying chamber, a bypass conduitextending from said vent stack to said enclosure for passing heated airto the latter, and means for passing heated air from said enclosure backdown into said drying chamber, the improvement which comprises: heatexchange water pipe means positioned in said enclosure to be heated bythe hot air flowing therethrough from said bypass conduit to said dryingchamber; and means connecting said heat exchange water pipe meansbetween a water supply and a hot water tank for preheating the watersupplied to the latter.
 4. A laundry system comprising a hot water tankfor supplying hot water to washers; water supply means for said tank; aplurality of dryers, each having a laundry drying chamber, a vent stackextending up from said drying chamber, an enclosure above said dryingchamber, a bypass conduit extending from said vent stack to saidenclosure for passing heated air to the latter, and means for passingheated air from said enclosure back down into said drying chamber; aplurality of heat exchange water pipes positioned respectively in saidenclosures to be heated by the hot air flowing therethrough from thecorresponding bypass conduit to the respective drying chamber; and meansconnecting said heat exchange water pipes in series with each otherbetween said water supply means and said hot water tank to preheat theWater supplied to the latter.